retroarch

home/common/programs/gaming/default.nix

@@ -17,7 +17,10 @@ let
   cfg = config.custom.gaming;
 in
 {
-  imports = [ ./moonlight.nix ];
+  imports = [
+    ./moonlight.nix
+    ./retroarch.nix
+  ];
 
   options.custom.gaming = {
     enable = lib.mkEnableOption "user-space gaming tools (launchers, Proton mgmt, MangoHud)";

home/common/programs/gaming/retroarch.nix

@@ -0,0 +1,80 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+# RetroArch — libretro frontend/emulator, plus standalone Dolphin & PCSX2.
+#
+# Cores are managed declaratively through `retroarch.withCores`. The in-app
+# Online Updater / Core Downloader is compiled out of the nixpkgs build
+# (--disable-update_cores), and the libretro buildbot cores wouldn't run on
+# NixOS anyway (generic-Linux binaries linked against FHS paths). So cores come
+# from nixpkgs' `libretro.*` set and are baked into the wrapper — add or drop a
+# system by editing the list below.
+#
+# ROMs and BIOS/firmware are still supplied by hand:
+#   * roms   -> ~/roms                      (game files)
+#   * system -> ~/.config/retroarch/system  (BIOS dumps: PS1, Saturn, DS, CD, …)
+# Both are seeded as empty writable dirs via `.keep` placeholders, so
+# home-manager creates the trees without owning their contents.
+#
+# GameCube/Wii and PS2 are installed as the standalone emulators (dolphin-emu,
+# pcsx2) rather than libretro cores — those cores exist but the standalones are
+# far better maintained and less finicky.
+#
+# WebDAV cloud sync is configured in the RetroArch UI (Settings > Cloud Sync):
+# no server URL or credentials live in this repo, since there's no secrets
+# tooling here and the Nix store is world-readable.
+#
+# Gated by its own option, independent of `custom.gaming.enable`, matching the
+# moonlight module next door.
+let
+  cfg = config.custom.gaming;
+in
+{
+  options.custom.gaming.retroarch = lib.mkEnableOption "RetroArch (declarative cores) + standalone Dolphin/PCSX2";
+
+  config = lib.mkIf cfg.retroarch {
+    home.packages = [
+      (pkgs.retroarch.withCores (
+        cores: with cores; [
+          # Nintendo
+          mesen # NES
+          snes9x # SNES
+          gambatte # Game Boy / Color
+          mgba # GBA
+          mupen64plus # N64 (Mupen64Plus-Next)
+          melondsds # DS
+
+          # Sega
+          genesis-plus-gx # SMS / GG / Genesis / Mega Drive / Sega CD / SG-1000
+          picodrive # 32X
+          beetle-saturn # Saturn
+          flycast # Dreamcast / NAOMI
+
+          # Sony
+          beetle-psx-hw # PS1 (HW upscaling)
+          ppsspp # PSP
+
+          # Handhelds / misc
+          beetle-pce # PC Engine / TurboGrafx / CD
+          beetle-wswan # WonderSwan
+          beetle-ngp # Neo Geo Pocket
+          beetle-lynx # Atari Lynx
+          beetle-vb # Virtual Boy
+
+          # Arcade
+          fbneo # FinalBurn Neo
+        ]
+      ))
+
+      # Better as standalones than their libretro cores:
+      pkgs.dolphin-emu # GameCube / Wii
+      pkgs.pcsx2 # PS2
+    ];
+
+    home.file."roms/.keep".text = "";
+    xdg.configFile."retroarch/system/.keep".text = "";
+  };
+}